Oblitosaurus bunnueli

Oceanotitan dantasi

Ohmdenosaurus liasicus

Ojoceratops fowleri

Ojoraptorsaurus boerei

Oksoko avarsan

Olorotitan arharensis

Omeisaurus junghsiensis

Ondogurvel alifanovi

Oohkotokia horneri

Opisthocoelicaudia skarzynskii

Orkoraptor burkei

Ornatops incantatus

Ornithodesmus cluniculus

Ornitholestes hermanni

Ornithomimus velox

Ornithopsis hulkei

Orodromeus makelai

Oryctodromeus cubicularis

Osmakasaurus depressus

Ostafrikasaurus crassiserratus

Ostromia crassipes

Othnielosaurus consors

Ouranosaurus nigeriensis

Overoraptor chimentoi

Overosaurus paradasorum

Oviraptor philoceratops

Owenodon hoggi

Oxalaia quilombensis

Ozraptor subotaii